1. Field of the Invention
The present invention relates to a gate valve apparatus, or in particular to a gate valve apparatus comprising an elastic seal member inserted into a pipe by way of a through hole formed in the peripheral wall of the pipe, a pressure member for elastically deforming the elastic seal member inserted in the pipe, by pressing it from the direction of insertion, a drive shaft formed in the shape of a rod along the direction of insertion to move the pressure member along the direction of insertion, and a movable member for pressing the elastic seal member into contact with the inner wall surface of the pipe in the direction crossing the direction of insertion, wherein the elastic seal member is kept in close contact with the inner wall surface of the pipe by the elastic deformation of the elastic seal member and a support member supporting the elastic seal member thereby to gate the internal flow path of the pipe.
2. Description of the Related Art
A valve body for suspending water supply in the pipe as disclosed in Japanese examined Utility Model Publication No. sho 64-3909, for example, is known as a gate valve apparatus described above. This apparatus is used for reducing the water supply-suspended area as far as possible at the time of repairing the various pipes including the water pipe.
First, a through hole is formed in the peripheral wall of an upper part of the pipe. The gate valve is fixedly inserted into the pipe by way of the through hole thereby to suspend the water flow in the pipe.
Specifically, the elastic seal member is inserted into the pipe by way of the through hole. At the time point when the lower surface of the elastic seal member comes into contact with the inner wall of the pipe, a gap exists between each the left and right sides of the elastic seal member and the inner wall surface of the pipe. This is by reason of the fact that the size of the through hole formed in the inner wall surface of the pipe is required to be smaller than the diameter of the inner wall surface of the pipe. After inserting the elastic seal member to the lowest position, the elastic seal member is brought into pressure contact with the inner wall surface of the pipe in the direction crossing the direction of insertion thereof through a movable member by the action of a pressure member. As a result, the elastic seal member can be kept in close contact with the whole periphery of the inner wall surface of the pipe.
For inserting the gate valve, a gate valve apparatus is required to be mounted on the pipe. The members making up the gate valve apparatus including the elastic seal member, the pressure member and the movable member are arranged in a case member, and the gate valve apparatus can be mounted on the pipe through the case member. Normally, before inserting the gate valve, each member is set at the upper part of the pipe. Specifically, a space for accommodating the members including the elastic seal member is required in the upper part of the pipe. As a result, the size of the gate valve apparatus is determined taking the process of mounting it on the pipe and the space for accommodating the members into account. Thus, a space extending in vertical direction is required.
The object of this invention is to reduce the vertical size of the gate valve apparatus as compared with the prior art. In view of this, the present inventors have discovered that the vertical size of the gate valve apparatus can be reduced by utilizing the space as effectively as possible in the setting immediately before insertion of the gate valve configured of the elastic seal member, etc.